In a small saucepan, bring the cream and espresso powder to a boil over high heat, stirring continuously.

Meanwhile, in a food processor, combine the chocolate and sugar and pulse until the chocolate is finely ground. Add the egg, vanilla and salt and pulse to a paste. With the machine on, carefully add the hot cream in a steady stream and blend until smooth and silky, about 1 minute.

Transfer the pudding to the ramekins and freeze until firm, at least 20 minutes, or refrigerate overnight. Serve with whipped cream and chocolate curls.